Is there a reason why you insist on using BGE? It looks like the game that you are making is two dimensional; Blender by nature is 3-D software, thus may not be the best option for a 2-D game.
If the reason is because of old hardware that you mentioned in your last post, then you should take a look at Godot. It works quite well on slow computers (Or so I’ve heard) and has support for OpenGL 2.x, which means it should run on old graphics cards. It also has much more modern tools available that would help you in this instance, such as built-in pathfinding. Even for a 3-D game, Godot may be a better option, depending on the graphical complexity of the game you’re making, of course.
Godot also supports scripting in a Python-like language, which means you won’t have to do too much in terms of learning a new programming language coming from BGE, which also uses Python.